As a technique to improve a viewing angle dependence of a γ-characteristic in a liquid crystal display device, a pixel dividing method (a multi-pixel structure) in which a plurality of pixel electrodes are provided in a single pixel has been developed. The viewing angle dependence of a γ-characteristic is a difference between (i) the γ-characteristic when the liquid crystal display device is viewed from the front and (ii) the γ-characteristic when the liquid crystal display device is viewed at oblique angles.
FIG. 30 is a plane view illustrating an arrangement of an active matrix substrate employing the pixel dividing method, disclosed in Patent Literature 1. When an active matrix substrate 900 is viewed in a plane manner, (i) a retention capacitor line (924a, 924b) is provided so as to correspond to a space between two pixel regions adjoining each other in a direction along a data signal line 914 (hereinafter referred to as a column direction); (ii) a scanning signal line 912 is provided so as to cut across a center of a pixel region; and (iii) a first pixel electrode 918a and a second pixel electrode 918b are provided on sides of the scanning signal line 912, respectively, such that (a) the first pixel electrode 918a is sandwiched between the scanning signal line 912 and the retention capacitor line 924a and (b) the second pixel electrode 918b is sandwiched between the scanning signal line 912 and the retention capacitor line 924b. The first pixel electrode 918a is connected to a drain electrode of a first transistor 916a, and the second pixel electrode 918b is connected to a drain electrode of a second transistor 916b. The first and second transistors 916a and 916b are connected to the same data signal line 914 and the same scanning signal line 912. Each of the pixel electrodes (918a and 918b) has a slit 918s, and the slit 918s serves as a structure for regulating liquid crystal orientation in a case where a liquid crystal display device is constructed by use of the active matrix substrate.
In the active matrix substrate, a capacitor electrode 932a is provided so that the capacitor electrode 932a, and the retention capacitor line 924a overlap each other. Further, a capacitor electrode 932b is provided so that the capacitor electrode 932b and the retention capacitor line 924b overlap each other. The capacitor electrode 932a is connected to the drain electrode of the first transistor 916a via a drain lead line 927a, and the capacitor electrode 932b is connected to the drain electrode of the second transistor 916b via a drain lead line 927b. 
The capacitor electrode 932a is connected to the first pixel electrode 918a via a contact hole 911a, and the capacitor electrode 932b is connected to the second pixel electrode 918b via a contact hole 911b. That is, a retention capacitance is formed between (i) the capacitor electrode 932a connected to the first pixel electrode 918a and (ii) the retention capacitor line 924a, and a retention capacitance is formed between (iii) the capacitor electrode 932b connected to the second pixel electrode 918b and (iv) the retention capacitor line 924b. Moreover, as mentioned above, one retention capacitor line is provided so as to correspond to a space between two adjacent pixel regions. In other words, one retention capacitor line is shared by two adjacent pixel regions.
In a case where such an active matrix substrate is used in a liquid crystal display device, the same potential is once written in the first and second pixel electrodes 918a and 918b. However, it is possible to make effective potentials of the pixel electrodes 918a and 918b different, for example, by controlling potentials of the first and second retention capacitor lines 924a and 924b so that phases of the potentials are opposite to each other. This results in that, for example, a bright sub pixel can be formed by the first pixel electrode 918a and a dark sub pixel can be formed by the second pixel electrode 918b. Examples of related well-known documents are Patent Literatures 2 through 4 as below.